200 years ago, Aeolia Schoenberg first developed the GN drive T (Tau drive). However, in the course of more extensive research, he found that the red-colored GN particles harbored various effects detrimental to the human body due to its instability. He proposed the need to develop a filtration system that would convert the red GN particles to a stable state harmless to human beings. After countless experiments and accidents, he ultimately completed the equipment known as TD Blanket.
However, manufacturing the TD Blanket required a great period of time and a special environment. There was no choice but to relocate the entire production facility, arousing internal dissent questioning the need for the TD Blanket, and thus created a split within CB over the differing attitudes towards the GN-drive. In the chaos of approximately 80 years ago, the supporting faction destroyed the original facility and migrated elsewhere, at the same time executing a portion of the rebelling faction, including their living CPU (quantum computing system?). However, a portion of the data terminal still remained. (I think something was mistranslated during the JP->CH translation, as this doesn't link too well with the flashback we saw. Or maybe there's something else.)
As such, only the GN drives installed with a TD Blanket could be formally called a "GN drive," whereas those without were pseudo-GN Drives (can't translate this properly). The pseudo-GN drives took less time to manufacture, its performance on par to that of a true GN drive. However, Aeolia Schoenberg believed that so long as the pseudo drives continued to emit more and more red particles, the solar furnance's output will ultimately falter and collapse (look up star death to see what happens when a star dies).
TD Blankets not only protected humans from the harmful effects of the red particles, but also increased the performance of the GN drive, and allowed it to generate potentially unlimited energy. However, due to the nature of the machine, there still existed the possibility of the TD Blanket being ineffective at controlling the harmful nature of the red particles, thereby creating large and unlimited quantities of red particles from the GN drive in an explosive manner. The Gundam takes advantage of these situations by applying them to the weapons system in a mode called "Trans Am," believed to be able to increase its normal speed many times over, the ultimate offensive weapon of the GN drive.
Because the Trans Am mode exposes the pilot to the harmful red particles, only in conjunction with the resource-intensive GN Arms class equipment can (or should? no indication in source) Trans Am mode be used. Trans Am mode can only be activated under a Veda-based control system, thereby forever safeguarding the Gundam's secret.